Light altering device

ABSTRACT

A line producing system includes an input beam of radiant energy that enters a side of a low cost, radiant energy altering device. The radiant energy emerges from the light altering device radiating in a nearly 360 degree disc pattern forming a ring of ever expanding light.

CROSS-REFERENCE TO RELATED APPLICATION

This is a divisional of U.S. application Ser. No. 09/728,756 filed Dec.4, 2000 now U.S. Pat. No. 6,833,962 by the same inventor, and claimspriority therefrom. This divisional application is being filed inresponse to a restriction requirement in that prior application andcontains rewritten and/or additional claims to the restricted subjectmatter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the field of radiation manipulation. Inparticular, the invention relates a method and apparatus for altering abeam of light or radiant energy.

2. Description of Related Art

Heretofore, light has been manipulated to produce an alignment fieldwith laser based equipment as shown in U.S. Pat. No. 3,588,249 where acollimated laser beam is rotated 360 degrees about an axis to establishan alignment plane. Remote receivers in the vicinity may detect thelaser beam as it sweeps past, and provide a visual or audible indicationwhen they are aligned in the laser plane. While this rotating beacontechnique provides results that are quite useful over long ranges, thecost of the mechanical and optical structures for implementing thetechnique with the desired amount of accuracy is relatively high. Also,the plane is more difficult to locate if the receiver is moved throughthe plane before the beam strikes its detector.

An improvement is disclosed in U.S. Pat. No. 4,674,870 that includes alaser alignment system employing a transmitter and one or morereceivers. The transmitter produces an alignment field by projectinglaser energy in a non-planar reference cone, and the receivers locatethis reference cone with photodetectors. The laser energy in thealignment field is modulated at 8 kHz and the signals produced by thephotodetectors are filtered and amplified to increase the range of thesystem. Each receiver operates a display, which indicates when it isaligned in the reference cone, and it produces an out-of-levelindication when the transmitter is not properly aligned.

A transmitter for an alignment system is shown in U.S. Pat. No.4,679,937 in which a field of electromagnetic radiation is propagated ina non-planar reference cone. The transmitter includes a source forproviding a collimated beam of electromagnetic radiation directedparallel to a beam axis. A cantilever strand supports a bob within thebeam. The bob has a conical reflection surface to reflect the collimatedbeam conically. Optimally, the cantilever stand and bob are chosen toprovide a deflection between the bob and plumb which is substantiallyone-half of any angular error between the beam axis and plumb. In apreferred form, a housing surrounds the bob and has inner and outersurfaces, which minimize temperature effects on the orientation of thereference plane. In addition, detectors are provided to sense when theangular error between the beam axis and plumb is outside of anacceptable range. Other leveling devices are shown in U.S. Pat. Nos.5,914,778; 5,940,557; 5,994,688; 6,005,719 and 6,009,630.

Obviously, in view of the above prior art, there is still a need for acost effective level line system.

SUMMARY OF THE INVENTION

Accordingly, in one aspect of the present invention, a low cost,light-altering device in the form of a hollow tube is disclosed for usein an optical level line system. The system includes an input beam oflight or radiant energy that enters a side of the hollow glass tube.Light emerges from the tube radiating in a nearly 360 degree discpattern forming a disc of ever expanding light. When the light strikesan enclosed or circular surface, a bright line or ring of light isproduced on the surface. This ring can be generated for X, X and Y, andX, Y, and Z axes, by employing an individual light-altering device peraxis, thereby supplying a line or ring for each axis. The lines or ringsof light are ideally suited, for example, for laser line levelingapplications.

In another aspect of the present invention, an input beam of light orvisible radiation enters a side of a light-altering device in the formof a capillary array of small tubes. The light emerges from the arrayradiating in a nearly 360 degree disc pattern forming a disc of everexpanding light. When the light strikes an enclosed surface, a brightline or ring of light is produced on the surface. This ring can begenerated for X, X and Y, and X, Y, and Z axes, by employing anindividual light-altering device per axis, thereby supplying a line orring for each axis.

In a third aspect of the present invention, an input beam of light orvisible radiation enters a side of light altering device comprising afiber optic rod. The light emerges from the rod radiating in a nearly360 degree disc pattern forming a disc of ever expanding light. When thelight strikes an enclosed surface, a bright line or ring of light isproduced on the surface. This ring can be generated for X, X and Y, andX, Y, and Z axes, by employing an individual light-altering device peraxis, thereby supplying a line or ring for each axis.

In a fourth aspect of the present invention, a low cost, light alteringdevice is disclosed for use in an optical level line system. The systemincludes an input beam of light or visible radiation that enters a sideof the light altering device that includes a hollow tube within a hollowtube. The light emerges from the tubes radiating in a nearly 360 degreedisc pattern forming a disc of ever expanding light. When the lightstrikes an enclosed surface, a bright line or ring of light is producedon the surface. This ring can be generated for X, X and Y, and X, Y, andZ axes, by employing an individual light-altering device per axis,thereby supplying a line or ring for each axis.

These and other features and advantages of the invention are describedin or apparent from the following detailed description on the exemplaryembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the instant invention will beapparent and easily understood from a further reading of thespecification, claims and by reference to the accompanying drawings inwhich:

FIG. 1 is a top view of an exemplary embodiment of a light alteringdevice in accordance with the present invention that employs a hollowtube, rod or capillary member(s).

FIG. 2 is a top view of another exemplary embodiment of a light-alteringdevice in accordance with the present invention that employs a capillaryarray.

FIG. 3 is a top view of yet another exemplary embodiment of a lightaltering device in accordance with the present invention that employs ahollow tube within a hollow tube.

FIG. 4 is a top view of yet another exemplary embodiment of a lightaltering device in accordance with the present invention that employs afiber optic rod.

FIG. 5 is a top view of still another exemplary embodiment of a lightaltering device in accordance with the present invention that employs agap between a rod and a reflecting plane.

FIG. 6 is a top view of another embodiment of the present invention thatis adaptable to produce a light reference plane of less than 360degrees.

FIG. 7 is a side view of a light-altering device in accordance with thepresent invention that employs a plumb bob.

FIG. 8 is yet another embodiment of the light altering device of thepresent invention employing a concave or convex shaped reflector.

FIG. 9 is an embodiment of a light altering device of the presentinvention that employs a concave, conical or parabolic reflector havinga hole cut in its side to allow the projection of light.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, a novel Light Altering Device(LAD) and method is disclosed to alter a beam of light or radiant energyfrom laser sources. This LAD dramatically changes an input beam of lightor radiant energy's properties. As an example, a laser beam entering theLAD is altered such that the light emerges radiating in a substantially360 degree disc pattern. This pattern can be obtained employing avariety of materials and geometries. One exemplary embodiment of thepresent invention employing a LAD is shown in FIG. 1. Here, a laser beam12 of laser 10 is shown entering the side of a LAD 15 in the form of ahollow glass tube 16. Light emerges from tube 16 radiating in thedirection of arrows 11 in a 360 degree disc pattern 17. Thus, a disc isformed of ever emerging light. An enclosure, for example, a circularscreen placed a given radius from the tube will allow an observer toview a bright ring of light on the screen surface. In addition, theuniformity of the light distribution around the radius is quite uniform.The light ring still maintains the optical properties of the directedbeam. That is, polarization of the directed beam remains the same aroundthe radius of the ring of light. Also, if the directed beam is such thatit is focussed to a point 3 meters from where the tube may be inserted,when the tube is inserted the focal point remains relatively unchanged.

A tube 16 made of glass, plastic, gelatin, etc., with the properdiameter, wall thickness, index of refraction, etc., with a red laserinput, can produce an emerging dotted ring of red light. That is, ablack and red series of dots (dashes) around the disc will result. Theinterference and/or diffraction properties of light are responsible forthis effect.

In another embodiment of the present invention in FIG. 2, LAD device 15includes a capillary array 20 of hollow glass tubes. As shown, laserbeam 12 of laser 10 enters a side of capillary array 20 with lightradiating from the capillary array in a disc pattern of about 360degrees. Thus, again a disc is formed of ever emerging light 17 in thedirection of arrows 11. A circular screen placed a given radius from thearray will again allow an observer to view a bright ring of light 17 ona surface of the screen.

In the embodiment of the present invention shown in FIG. 3, laser 10directs an input laser beam 12 into a surface of LAD 15 which comprisesa combination of hollow tubes 30 and 31, with hollow tube 30 placedwithin hollow tube 31. As a result, light radiates from the hollow tubes30 and 31 in a disc pattern of approximately 360 degrees forming an everemerging light 17 in the direction of arrows 11. A circular screenplaced a given radius from the tubes will again allow an observer toview a bright ring of light 17 on a surface of the screen.

In the embodiment of the present invention shown in FIG. 4, laser 10directs an input laser beam 12 into a surface of LAD 15 which comprisesa fiber optic rod 25. As a result of laser beam 12 striking the surfaceof fiber optic rod 25, light radiates from the rod in the direction ofarrows 11 in a disc pattern of approximately 360 degrees forming an everemerging ring of light 17. A circular screen placed a given radius fromthe tubes will again allow an observer to view a bright ring of light 17on a surface of the screen. A fiber optic rod 6 mm in diameter displaysa fairly uniform brightness around the rod where the beam enters. Thisscattered light seems uniform and so does the emerging beam. However,there is no visible light emerging from either of the polished ends ofthe rod. Therefore, there is minimal light loss into the fibers, therebyindicating an efficient reflection at the cladding interface. It isbelieved that there are multiple reflections within and/or around theoutside of the fiber optic rod. The light, in this case, reflects offsmall micron diameter fibers, for example, about 13 microns, allencircling and contained in the ¼ inch diameter fiber optic rod, withouta significant drop in light energy. That is, the total power emitted bythe fiber optic rod is quite close to the power of the light directedinto the rod. However, some scattered light is noticed around thecircumference of the rod, but is only as wide as the entering light beamand does not appear to be very significant.

A method for efficiently utilizing almost all of the light generated,while providing a beam over 180 degrees or so, is accomplished byemploying a light altering-device in contact with a glass surfacecontacting a mirror with a hole through it. In the embodiment of thepresent invention shown in FIG. 5, a laser 10 directs a laser input beam12 through a channel 16 cut through mirror 13. Laser beam 12 enters aglass member 14 as it is directed towards LAD 15 in the form of a fiberoptic rod 18. Glass 14 serves as a spacer member to force a controlledand parallel gap between LAD 15 in the form of fiber optic rod 18 andreflecting plane 19 of mirror 13. As shown by arrows 11, some light isreflected off the glass surface, while other rays of light are directedtoward the mirror, striking the mirror, and reflecting off the mirror inmultiple directions whereby it is multi-reflected to provide an emergingsemi-circular beam of 180 degrees, or so. All of these reflections occurin the same plane that the beam strikes the LAD. Of course, using amirror without a hole or channel can be employed by aiming thelaser-input beam directly at the LAD from the side. That is, at an angleslightly greater than 90 degrees from the laser beam 12 shown in FIG. 5.

It should be understood that other methods may be employed to alterlight beams for special purposes or special results. For example, toimprove beam uniformity about its circumference, mirrored coatings maybe applied to the appropriate regions on the outer surfaces of the rodor tube(s) to direct light to the less bright regions of the beam. Also,the altering of the cross-sectional shape of the rod or tube to be oval,spherical, or have a flat areas on the circumference, etc., can providespecial beneficial light patterns.

LAD units may also employ light sources other than lasers forillumination sources. This can include point or line sources, singlecolors, white light, etc. In fact, for special applications, multiplelaser or light sources can be employed such that each individual sourceis aimed directly into a single LAD, without the light losses typicallyassociated with uniting multiple light beams.

Hereinbefore, a LAD has been described that produces nearly a 360 degreecircle of light. In some instances, there are times when it ispreferable to employ only a portion of a circle of light, for example,90 to 180 degrees for line making purposes. In those instances, theembodiment of the present invention shown in FIG. 6 is employed thatcomprises a substrate 55 with a channel 16 therein and is aligned toanother substrate 57 orthogonally. LAD 15 is positioned at anintersection of substrates 55 and 57 on top of a mirrored face 13 of thesubstrates. In this configuration, a 90 degree portion of a circle iscreated by a beam 12 from laser 10 applied through channel 16 insubstrate 55. The laser beam contacts LAD 15 and light emerges from theLAD, as shown by lines 17, initially in all directions as shown byarrows 11. However, mirrors 13 redirect the light such that it iscontained approximately within the 90 degrees formed by the mirrors. Bymoving mirror 57 relative to mirror 55 a larger angular coverage can beattained as shown by arrow 58. It should be understood that substrates55 and 57 could be made of glass with mirrors 13 being placed on theopposite face of the substrates.

In FIG. 7, a plumb bob laser leveling apparatus 60 is shown thatincludes a LAD 15 positioned within plumb bob 62. Spherical plumb bob 62is fashioned having two hemispheres separated by a narrow transparentmember 64 which encompasses the 360 degrees of the sphere's equator. ALAD 15 is positioned within the space provided between the two halves ofthe bob in order to provide a circle of light. The bob can be suspendedfrom a string, a flat metal tape, e.g., a measuring tape in conjunctionwith a metal ring 69, or attached to a wall, suspended from a door frameor ceiling, or operate hanging from a cross arm rod attached to a baseor cantilevered from the base resting on a floor. The bob can have mostany shape and is unique in that it automatically rests in a straightdown position. This principle dictates that a plane cut through the boborthogonal to the string direction can be useful for floor leveling.Thus, a LAD unit properly aligned/positioned within the bob allows theLAD to produce a circle of light for reference purposes, e.g., toachieve floor flatness. While it is preferred to center the weightdistribution of the laser and LAD within the housing of the bob andspacer members, it may not be critical, since it should be much lessthan the mass of the bob. The bob weight can significantly dominate overthe weight distribution of the LAD.

In operation, laser 10 supplies a beam of light 12 onto mirror 65 thatdeflects the light in a straight line into LAD 15. The laser beamemerges from LAD 15 as an ever-expanding ring of light in the directionof arrows 11. For best results, the mirror should be slightly wider thanthe beam width.

Concave and convex cylindrical reflectors can be useful for generatingunique light patterns. In the method and apparatus shown in FIG. 8,laser beam 12 of laser 10 passes through a hole in the concave andcylindrical reflector 70 to strike LAD 15. As the ever expanding lightemerges in the direction of arrows 79, some of it strikes and reflectsoff mirrored surface 71 of the concave reflector 70. Mirrored surface 71is mounted on a glass substrate 74. The remaining light continues untilit emerges at an angular extent that is determined by the parametersbetween the LAD 15 and mirrored reflector 71. That is, altering thereflector's shape, size, focal point, length, curvature, etc., allowsfor obtaining any desired angular extent required. For example, thereflector's angular extent could be altered by cutting it off at marks72 and 73. Since the reflected light combines with the emerging light inthe same plane, the emerging ring segment brightness is increased andmade more uniform. Alternatively, a convex cylindrical reflector 78shown in dotted lines may be employed to control the angular extent ofthe emerging light disc and function to give a wider angle ofreflection.

Incorporating a LAD 15 on the optical axis of a concave, conical orparabolic reflector 80 having a slot (or hole) cut into its side isillustrated in FIG. 9. A laser beam 12 from laser 10 is directed throughthe slot striking LAD 15 producing a ring of light 17 that in turnstrikes the inside of reflector 80. The light ring is reflected andconverged and then diverges, as shown by arrows 11, to strike a polishedsurface 86 of cone 85 placed on an axis with the reflected beam. Thering of light after reflection from surface 86 of cone 85 is directed soas to be parallel to the ground, thereby enabling its use for levelreferencing purposes. With the structure fabricated within a bob, by itsnature, the unit would be self leveling.

Other light altering devices may be constructed with monofilament fishline, single or multiple optical fibers, thin wires, or numerous otherthin filament materials. These elements may be operated in vacuum, air,and be used in liquids, plastics, and glass and employed with or withoutcladding and/or covering materials. It is also contemplated that thecross sectional shapes of the aforementioned light altering devices maybe altered for special purposes and that reflective coatings may also beapplied to the light altering devices for special usages, for example,to improve emerging beam uniformity and efficiency.

It should now be understood that a low cost, radiant energy alteringdevice has been disclosed that is a few millimeters in diameter andchanges an input beam of radiant energy into an output in a discpattern. The radiant energy altering device is low in cost and cancomprise a variety of materials and geometries, including hollow glasstubes, fiber optic rods, tubes within tubes, etc. The altering device isnot limited to input of laser energy, be it coherent or incoherent,multiple wavelength, i.e., broadband, colored or white, point or linesource.

While the invention has been described in conjunction with the specificembodiments outlined above, it is evident that many alternatives,modifications and variations will be apparent to those skilled in theart. Accordingly, the preferred embodiments of the invention as setforth above are intended to be illustrative and not limiting. Variouschanges may be made without departing from the spirit and scope of theinvention as defined herein.

1. An apparatus for producing a line of approximately 360° within apredetermined plane, comprising: a laser source adapted to produceradiant energy; a laser output altering device, and wherein radiantenergy projected from said laser source into said laser output alteringdevice emerges from said laser output altering device within saidpredetermined plane in an ever expanding circle of light; and a plumbbob with said laser output altering device positioned between portionsof said plumb bob; wherein said laser output altering device is in theform of a hollow tube within a hollow tube.
 2. The apparatus of claim 1,including a mirror, and wherein radiant energy from said laser source isprojected into said mirror and then into said laser output alteringdevice.
 3. The apparatus of claim 2, wherein said mirror is angled withrespect to radiant energy emerging from said laser source.
 4. Theapparatus of claim 2, wherein said mirror includes a reflecting surface,and wherein said reflecting surface of said mirror is spaced from saidlaser output altering device.